This study is an assessment of oral-motor kinetics to evaluate the hypotheses that (1) the greater the efficiency of milk ingestion, the less work will be performed and (2) breastfeeding is not more work than bottle feeding. (NRSU protocol). Over the last 5 years, the following results were achieved:1)Development of a nipple/bottle apparatus which allows the monitoring of the sucking behavior in infants. As discussed in the new application, this methodology is being adaped so that it can be used as a clinical tool. 2)The development of a breastfeeding system to monitor sucking has not evolved as quickly as that for bottle feeding. This will continue in the present application. 3)With nipple/bottle system, we have characterized the devlopment of sucking using premature infants as they mature and were introduced to oral feeding. A better understanding of the coordination of suck, swallow and respiration has also been achieved. We are in the process of evaluating whether these developmental characteristics can help us identify specific sucking dysfunctions exhibited by infants with feeding disorders. This will have clinical importance, particularly for occupational therapists working with this population of infants. Studies will continue in this area as described in the present application. The renewal of this application is a logical continuation of the original study. Over the last 5 years, there were 3 major amendments: 9/19/94: the use of a Mikro-tip sensor transducer for the monitoring of the suction component of sucking. 2/19/97: the development of a finger pressure device for the assessment of non-nutritive sucking. 10/13/97: the permission to use this tool in the clinical setting without the need of parental consent.